Cut-out for electric-arc lamps



(No Model.)

B. THOMSON.

GUT-OUT FOR ELECTRIC ARC LAMPS. No. 307,819. Patented Nov. 11, 1884.

Jig. 2.

mm L m mm.

74%1esses:

UNITED STATES PATENT Orricn.

ELIHU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

CUT-OUT FOR ELECTRIC-ARC LAMPS.

EPZZCIFICATEON forming part of Letters Patent No. 307,819, dated November 11, 1884.

Application filed April 12, 1884.

T0 aZZ 107mm it may concern:

Be it known that I, ELIHU Tnorrson, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements inCut-Outs for Electric- Arc Lamps, of which the following is a specification.

My invention relates to apparatus for auto IO matically forming a shunt or safety branch around the electrodes of an electric-arc lamp in case of an abnormally-long are.

My invention is designed more especially for use with electric-arc lamps arranged in se- I 5 rics upon an electric circuit, and is intended to furnish a simple and effective device where by the lamps may be automatically cut out independently of one another, as with those out out devices in which the shunt or safety branch is controlled by a magnet of high resistance in a derived circuit around the carbons.

The object of the invention is also to give independence of action to the cut-out device ofa number of arc lamps in the same circuit, when the cutout switches are controlled by electroanagnets in the main or principal circuit with the carbons, as in the well-known Varley cut-out.

My invention consists in breaking the are of a lamp if it reach an abnormal length by the repellent or attracting influence of a magnetic field bearing on the are, and produced by the agency of a permanent or electro mag net, a solenoid, or other suitable device, and

thus calling into action the particular cutout apparatus of the lamp in which the abnormal arc occurs.

The cut-out apparatus may be a Varley or other cut-out apparatus of suitable kind to be acted upon by the disruption of circuit at the are.

Some of the ways in which my invention may be carried into practice are shown diagrammatically in the accompanying drawings.

The parts illustrated are of any desired kind, and the manner of mounting them in thelamp is immaterial.

The invention consists in the manner of electrically connecting and arranging the parts with relation to one another.

so as to effect a rupture of circuit, at which (No model.)

Figure 1 illustrates diagrammatically a way of carrying out the invention in connection with a Varley cutout. Fig. 2 is a modified arrangement for giving increased infiu- 5 5 once to the displacing-magnet at the time that the arc length ens abnormally. Fig. 3 shows an improved disposition and manner of mounting the displacing-magnet. Figs. at and 5 illustrate other modifications oftheinvention. Fig. 6 illustrates a device that may be employed for keeping the controlling device of the cut-out in unchanged relation to the arc while the lamp is in operation.

In Fig. 1, B indicates an electro-magnet in the main or principal circuit with the electrodes of an electric lamp whose are is indicated at E. The magnet B acts on its armature A against the force of a retractor to keep the contacts F of a branch or safety circuit, 7, around the lamp normally open, after the manner of the main-circuit magnet in the well-known Varley cutout.

M is a magnet suitably supported, so that one of its poles will be near the are and will exert a repellent or attracting eflect thereupon, according to the pole presented. At any time during burning it will displace an abnormallylengthened are produced by a failure to feed,

time the armature A,being released,is allowed to shunt the lamp through suitable contacts at F. Should the carbons after the extinguishment again come together, the magnet B will open the contacts at F and allow the lamp to resume its action.

In the modified arrangement shown in Fig. 2 the permanent magnet M is replaced by an electromagnet, M, which is brought into action by other agenciesas, for instance, by a derived-circuit elcctro-magnet, Dto break the are if it become abnormally long. The shunting or switching appliances for forming the path around the lamp are here omitted for the sake of simplicity. The coils of magnet. M are controlled by shunting contacts S, which are normally closed by the action of a spring, G, acting on the armature-lever carrying one of said contacts. The armaturelever is acted upon by the magnet D of high resistance in a derived circuit around the arc, while the contacts S close a shunt around the coils of II. lVhen the shunt at S is opened, the coils of M are in the lamp-circuit, as indicated, and said magnet is then energized and acts strongly upon the are to disrupt it. The electro-magnet D and retraetor G are adjusted so that when the arc becomes abnormally long the magnet will have suifieient power to open the contacts S, whereupon the magnet M immediately breaks the are, as before explained. It is not necessary that the current be permitted to How in coils of M only with abnormal arcs. The contacts S may open during normal arcs, or may be dispensed with, the current then flowing constantly in coils of M. The coils of M may be, if desired, in a derived circuit of high resistance around the are, as indicated in Fig. 5, so that its power to displace an arc will increase with the increased length of arc. The coil of M in this case may have a resistance of seven hundred ohms around an are which abnormally lengthened may be ten ohms.

In Fig. 3, M M indicate a two-branched or horseshoe magnet whose poles N S affect the are E and displace it. The magnet M M may be a portion of the frame of the lamp, as shown, and serve in whole or part to sustain the lower holder.

In Fig. i the coil O, properly arranged with relation to the are, is in the main circuit and att'ects the are at E to drive the latter aside until it breaks circuit. At the instant this occurs the current forces its way through the film of a film cut-out, indicated at K, and construeted as described in a prior application for patent filed by me February 25, 1882, No. 53,726, thus forming the safety-circuit around the carbons.

K indicates the film of insulating material which normally keeps the electrodes a I) out of connection, one or both of the latter being preferably acted upon by a spring. The film is of thin tissue-paper oiled, or of other insulating material. \V hen the difference of potential between a and b, owing to breakage of the are or other cause, becomes suffieiently high, the current breaks through the insulating-film and the connection between the electrodes a '1) is thus formed.

In order to keep the magnetic field constantly in the same relation to the are in an ordinary or non-focusing electric lamp, the magnet may be supported from a mechanism that shall permit it to shift in position correspondently with the shifting of the are by consumption of the carbons. Such an arrangement is indicated in Fig. 6, and is sub stantially the same as the one shown in a prior application filed by me December 18, 1883, No. 114,967.

It indicates the carbon-carrier, gearing with wheel,f, keyed to or upon the same shalt with the wheel 9, which latter gears with a bar, d, supporting the magnet M. The wheels are so proportioned that the downward movement of the magnet shall exactly correspond with the downward shitting of the are due to the consumption of the electrodes.

Other mechanical devices may obviously be used for permitting the desired movement of the magnet or solenoid.

hat I claim as my invention is 1. In an electric-arc lamp, the combination, with cut-out devices for forming a branch circuit around the lamp, of a magnetic field near the are, whereby it may be displaced or ruptured, as and for the purpose described.

2. The combination, with the electrodes in an electric-arc lamp, of a bar magnet or mag nets arranged parallel to said electrodes for the purpose of displacing the are.

3. The GOll'lillll2li=l0ll,\\ltll the electrodes in an electric lamp, otf an aredisplacing magnet or solenoid lnwing its coils in a derived circuit around the arc.

4. The combination, with a short or shunt circuit closer, ot' a magnet in the carbon-circuit for keeping the circuitcloser open, and means, substantially as described, whereby the are may be displaced through the influence ot' a magnetic field.

Signed at Lynn, in the county 01' Essex and State of llIassachnsetts, this 7th day of April, 1LT). 1884-.

IDLIHU TIIIOUSON.

\Vitnesses:

W. O. \Rucntunrm, E. 13. Dean. 

